Two weeks ago, a video leaked out legit-looking screenshots claiming to be an alpha build of Fight Night Champion's first downloadable content. EA Sports is announcing what's in the first pack tomorrow, but if this video is real, it's five all-time great fighters, plus Cowboys Stadium as a venue.

Heavyweight legends Joe Louis and Rocky Marciano, who have yet to appear in Fight Night, are included in the pack if this video is to be believed. Floyd Patterson returns; he had been in Fight Night Round 3 but was absent from Round 4. And Jack Johnson, whose bout 101 years ago with James J. Jeffries coined the term "Fight of the Century," will also debut.

Cowboys Stadium, you might recall, was a venue in EA Sports MMA, so its inclusion here is not that surprising. It'll be another big time title-fight arena, joining the MGM Grand, the Thomas & Mack Center and Madison Square Garden "New York Arena" in the main game.

Kotaku contacted EA Sports for comment. We'll update here if any is given. Officially, the publisher has said it will reveal all about its first DLC package tomorrow during a live chat from 4 to 5 p.m. Pacific. The game's first title update will arrive when the DLC is released. It will include several adjustments made at the suggestion of the community, including to punching accuracy, combination punching, hit reactions and health - with regular punches doing more damage.